Whether Airwire is “DCC” depends on how narrowly you want to define DCC. If you take the traditional approach that the term “DCC” only applies to the throttle>command station>track>multiple decoder distribution model, then under that model, Airwire is not “DCC.” Neither is using the Airwire or G-wire transmitter with with a G-wire/QSI decoder. Airwire (and manufacturers of similar wireless systems) use a broader definition; one that applies “DCC” to the command protocol (encoding and data packets), divorcing it from any specific means of distribution.
More and more, these “non-traditional” DCC systems are becoming popular in the smaller scales as well as large scale. Northwest ShortLine sells their “Stanton S-Cab” system which uses a dedicated handheld transmitter to control generic DCC decoders via an onboard receiver wired directly to the decoder. (This is similar to the G-wire/QSI pairing.) Airwire’s “G3” and drop-in decoders are nothing more than a wireless receiver connected to a motor/function decoder no different than the G-wire/QSI or the S-Cab pairings.
Airwire and Tam Valley Depot sell receivers which control any generic DCC decoder just by hooking the output of the receiver to the track input of the decoder. With the Tam Valley Depot “Dead Rail System,” you can control the decoder either via an Airwire transmitter or by clipping their transmitter module to the rails of any “traditional” DCC-powered railroad. That allows you to use whatever command station you already have or might want to use, but not need the rails to get the command signals to the decoders. Airwire’s “Convertr” wireless receiver uses any Airwire handheld transmitter to control the decoders. Massoth has had a similar wireless receiver on their web site for a few years now, but it has yet to come to fruition.
The times, they are a changin’. The lines that used to exist between various control methods are disappearing as technology evolves and systems overlap more and more. The core command protocol is unchanged, so compatibility across manufacturers is maintained. That–to me–is a good thing. I used to be limited to various proprietary systems, but now I can use the transmitters I already own and control pretty much any DCC decoder on the market with them. Likewise, for those already invested in DCC, you can use your existing DCC command system and now broadcast the control packets to your decoders without even needing wires to the track. Good times!
In regard to your inquiry, I offered my thoughts on your similar thread a few days ago–just hook the motors of “Unit 2” to the motor output of the Airwire in “Unit 1.” Like others stated above, I also use fuses between the battery and control electronics. Cheap insurance. I usually use 5-amp fuses, but I’m not running 4 motors from one battery. Presuming these units haven’t been converted yet, can you run them and measure their current draw under regular track power at various voltages? That will give you some idea of what your needs would be. Another option would be to put fuses between the battery and electronics (10 amps) then 5-amp fuses between the electronics and motors of both units. That’s a definite “belt and suspenders” approach, but at 99 cents per fuse, it’s still cheap insurance even at three times the cost.
Later,
K